Will they stay? Friday’s massacre in a Parisian kosher supermarket has shone a spotlight on a scary reality: France’s Jewish community is under threat, and many may leave as a result. Prime Minister Manuel Valls says a mass exodus would be disastrous for France. But Jews are increasingly worried about anti-Semitism and Islamic extremism. And many feel the government — which is deploying thousands of police to Jewish schools this week — hasn’t been doing enough to protect them.